With her icy, unnerving stare and withering put-downs, Monica Galetti can turn chefs' legs to jelly.

The unexpected star of this year's Masterchef: The Professionals is quite possibly the scariest cook on television.

She may not swear like Gordon Ramsay or boil over like Marco Pierre White but she's left experienced contestants fluffing their flambés and goofing up their goujons.

Professional chefs must first impress her before they get a chance to cook for her boss, the legendary Michel Roux Jr. However, Monica, who works as Michel's sous chef, takes an awful lot of impressing.

But, really, how difficult can it be? I went along to Michel Roux's restaurant Le Gavroche to see if I could impress the culinary world's answer to Anne Robinson.

TROUT

Arriving at the three-Michelin-starred establishment near London's Hyde Park, she greets me with a smile.

I smile back. This will be a piece of cake.

"All you need to do is peel a prawn and bone a trout," she says as we walk to the kitchen. Music to my ears - until I clap eyes on the trout, which is an absolute monster, bigger than any I've ever seen.

With Monica peering over my shoulder, I get stuck in to the 4kg beast - and at first I don't think I'm doing too badly.

Sadly, Monica disagrees.

"Oh my dear Lord," she mutters as I hack at the trout's head with a carving knife. "Don't you know you should never hold a knife that way... you've got the angle totally wrong there... oh my word, what are you doing now?"

Not a good start. I'm sweating and my hands are starting to shake.

"Oh, no, that's not even, and you're leaving most of it on the bone. I would never be able to give that to Michel.

"You know what... just stop."

Gladly. I scrub my fingers in the sink, half-expecting more scathing criticisms of my hand-washing technique, but she doesn't say a word, which unnerves me even more.

Next, I try to peel a king prawn - but my confidence is shot to pieces and it keeps slipping out of my hand.

Hardly, I think. Scared of a prawn, me? No chance, although now I'm terrified of Monica. "If you can't even peel a prawn I don't think there's much hope for you and I wouldn't let you cook for Michel," she says. I can cook an omelette, I protest, but she's seen more than enough and allows me to give her a grilling instead.

Born in Samoa but raised in New Zealand, Monica needed her steely character when she told her disapproving father she wanted to be a chef.

She recalls: "He wasn't impressed. In my culture, cooking is not considered a career. It's something for the women who stay at home and cook for their families."

Monica completed a catering course and worked in restaurants in New Zealand before heading to Europe.

Now 34, she has worked for Michel for 10 years. She says: "I'm no different on the show to how I am here in the kitchen. It's easy to lose your temper when you're under pressure and someone makes a stupid mistake, especially when they don't own up to it straight away.

"I wouldn't go out of my way to make them cry but sometimes I've shouted or said a harsh word that might have made them cry.

REPUTATION

"It doesn't surprise me that people think I'm scary, but it is quite surprising to suddenly have this reputation outside the kitchen. Because when I'm not in work mode I'm not scary at all."

Monica - who is married to David, the head sommelier at Le Gavroche - admits she has often been on the receiving end of Michel's own fiery temper.

She says: "Has he made me cry? Many times. Again, it is under pressure and in the heat of the moment. You know that if you mess up two or three tables in a row Michel's going to let you know about it.

"When he shouts you know it's serious.

But at the end of the day he will tell you what you did wrong and how to put it right. That's how the contestants should see it."

Although she says she is flattered by calls for her to get her own show, and enjoys working with Gregg Wallace, she claims to prefer the kitchen to the cameras. "This is something that has come out of the blue," says Monica, who has a three-year-old daughter with David. "I never expected to be on TV and, even though I enjoy it, my passion is working in a busy restaurant kitchen."

Besides, she's woefully unprepared for the perils of fame.

"The other day I was shopping in Primark and someone recognised me from the show and came up to me. I quickly put the top back and rushed out!" Scariest cook on TV? She's a sweetie.

Masterchef: The Professionals, BBC2, tonight, 8.30pm. Michel and Monica will be at MasterChef Live, November 13-15, London Olympia. To book tickets go to www.mastercheflive.com or call 0844 579 3198.